It is known, referring to FIG. 1, to electrically charge a battery of an electric vehicle (2) using a battery charging system (3) that is connected to the vehicle (2). The charging system (3) includes a control box (4) connected to a vehicle coupler (5). The vehicle coupler (5) is attached to the vehicle (2) to charge the battery. The vehicle coupler includes a mechanical switch (6). When the mechanical switch (6) is closed, an electrical output changes state so that the vehicle (2) senses the presence of the vehicle coupler (5) and enables charging of the battery by the system (3). When a latch mechanism (not shown) is operated by a pulling of another trigger (not shown) or a pressing of a button (not shown), mechanical switch (6) is cycled, that is, mechanical switch (6) moves from a closed to an open position. When mechanical switch (6) is released, it returns back to its closed position. The contacts (not shown) of the mechanical switch (6) are subject to wear and may actually wear out with repeated use of the mechanical switch (6) that may lead to a decreased product life and require early undesired servicing of the mechanical switch (6). Additionally, a potentially unsafe situation may develop if the vehicle coupler (5) is disconnected from the vehicle (2) by an operator of the system (3) while the battery is simultaneously being electrically charged, otherwise known as a hot disconnect of the vehicle coupler (5). The electric circuit as shown in prior art FIG. 1 is described in a SAE J-1772 standard for hybrid electric vehicles and electric vehicles.
Hybrid electric vehicles and electric vehicles are gaining in popularity with consumers in the marketplace. And because these vehicles may use little or no hydrocarbon fuel, they rely more heavily on the energy provided by the vehicle's battery to power a vehicle along a road. As an energy charge state of the battery of the electric vehicle decreases, the battery may need to be electrically recharged back to a fully charged energy state. As electric vehicles become more prominent, the need for battery charging systems to recharge batteries for these vehicles increases. It is desirable to provide a battery charging system that eliminates the shortcomings of the prior art as shown in FIG. 1. It is also desirable to recharge a battery with a system that provides increased safety and convenience for a user of the battery charging system.
Accordingly, what is needed is a reliable battery charging system that provides increased safety and convenience for a human operator of the battery charging system.